package cn.edu.ctbu.demo01.service;

import cn.edu.ctbu.demo01.constant.REnum;
import cn.edu.ctbu.demo01.dao.StudentRepository;
import cn.edu.ctbu.demo01.entity.Student;
import cn.edu.ctbu.demo01.exception.RException;
import jakarta.transaction.Transactional;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Example;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class StudentService {
    @Autowired
    public StudentRepository studentRepository;

    /**
     * 读所有的学生列表
     *
     * @return List Student
     */
    public List<Student> getAll() {

        return studentRepository.findAll();
    }

    public Page<Student> getAll(Pageable pageable) {
        return studentRepository.findAll(pageable);
    }

    public Page<Student> getAll(Example<Student> example, Pageable pageable) {
        return studentRepository.findAll(example, pageable);
    }

    public Student findById(int id) {
        return studentRepository.findById(id).get();
    }

    /**
     * 新增学生
     *
     * @param student
     * @return
     */
    public Student add(Student student) {
        return studentRepository.save(student);
    }

    /**
     * 更新学生
     *
     * @param student
     * @return
     */
    public Student update(Student student) {
        return studentRepository.save(student);
    }

    /**
     * 删除学生
     *
     * @param ids
     */
//    public void delete(Integer id) {
//        studentRepository.deleteById(id);
//    }
    @Transactional
    public void deletebatch(Iterable<Integer> ids) {
        studentRepository.deleteAllByIdInBatch(ids);
    }

    public Student validateUsernameAndPassword(String sno, String password) throws Exception {


        List<Student> students = studentRepository.findBySno(sno);
        if (students.size() > 0) {
            Student student = students.get(0);
            if (student.getPassword().equals(password)) {

                //成功
                return student;
            } else {
                throw new RException(REnum.LOGIN_ERR);
            }

        } else {
            throw new RException(REnum.LOGIN_ERR);
        }
    }
}
